I'm not entirely sure why this is, but for some reason:

921935dc6404 ("drm/amd/powerplay: enforce display related settings only on needed")

Breaks runtime PM resume on the Radeon PRO WX 3100 (Lexa) in one the
pre-production laptops I have. The issue manifests as the following
messages in dmesg:

[drm] UVD and UVD ENC initialized successfully.
amdgpu 0000:3b:00.0: [drm:amdgpu_ring_test_helper [amdgpu]] *ERROR* ring vce1 test failed (-110)
[drm:amdgpu_device_ip_resume_phase2 [amdgpu]] *ERROR* resume of IP block <vce_v3_0> failed -110
[drm:amdgpu_device_resume [amdgpu]] *ERROR* amdgpu_device_ip_resume failed (-110).

And happens after about 6-10 runtime PM suspend/resume cycles (sometimes
sooner, if you're lucky!). Unfortunately I can't seem to pin down
precisely which part in psm_adjust_power_state_dynamic that is causing
the issue, but not skipping the display setting setup seems to fix it.
Hopefully if there is a better fix for this, this patch will spark
discussion around it.

Fixes: 921935dc6404 ("drm/amd/powerplay: enforce display related settings only on needed")
Cc: Evan Quan <evan.quan@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Rex Zhu <Rex.Zhu@amd.com>
Cc: Likun Gao <Likun.Gao@amd.com>
Cc: <stable@vger.kernel.org> # v5.1+
Signed-off-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>